People of Fatulla, in Narayanganj, have caught, beaten up and handed over to police three Islami Chhatra Shibir activists, who torched a bus with a firebomb.
Gun powder and five such bombs were recovered from them.
The incident took place on the Dhaka-Narayanganj-Munshiganj road in Kashipur area around 1pm on Saturday, Additional Superintendent of Police Mohammad Sazzadur Rahman said.
The arsonists were admitted to the Narayanganj Sadar Hospital, he said.
One of them, ‘Mahmud’, 25, was said to be in a critical condition.
The two others were identified as Fatulla unit chief of the pro-Jamaat-e-Islami student front Shihab Uddin, 19, and Abu Sayeed, 35.
Witnesses said passengers of the Dhaka-bound bus got off quickly when 10-15 people stopped it and started vandalising it.
The attackers set the bus ablaze with firebombs, they said.
Local people chased and caught three of them, they said.